Monday, March 19, 2012

It seems that market-based approaches to increasing housing affordability are at last getting widespread attention. Between Ed Glaeser's Triumph of the Cityand Matt Yglesias' The Rent is Too Damn High, a long-overdue conversation about the impact of land use regulations on the cost of housing is finally happening.

As an ally of those calling for an end to such policies as rent control and overly restrictive zoning, I hesitate to throw a bucket of cold water on these affordability strategies. They certainly would, over time, have a positive impact on housing supply. Whether New York can build its way up to affordability, though, is a more debatable question.

A basic point I'd raise is that in almost all times and places, the solution for urban population growth has not been vertical densification, but outwards expansion into greenfield areas. Historically, dramatic vertical growth was the product of exceptional circumstances, generally related to the presence of city walls paired with external military threats discouraging sub-urban construction, or the occasional imperial mega-city. The development of skyscrapers in the late 19th century looked to have the potential alter this longstanding pattern, but for several reasons, greenfield development still remains today the overwhelming source of accommodation for urban population growth:

The naturally slow pace of incremental infill developmentin a built-up area. Even where demand is very high, the process of acquiring parcels from a multitude of private owners, demolishing structures, and rebuilding, is slow and arduous in the best of times. The technological possibility of skyscrapers themselves may inflate land values, resulting in speculative holding that further deters redevelopment.

The opportunity cost of densification. Existing buildings, even of very low value, still represent a sunk cost now generating a reliable stream of income for a current or prospective owner. The new building must not only justify itself on its own terms, but justify itself in relation to the profits being earned on the existing building, less the time lost to construction.

Political opposition. It may be condemned as unfair, inefficient or narrow-minded, but as long as there are people living in neighborhoods, there will be people willing to oppose new and denser development in those same neighborhoods. That doesn't mean strategies to reduce neighborhood opposition to densification or to encourage infill shouldn't be pursued, but it does mean that, all else being equal, greenfield development will almost always present fewer political obstacles.

These factors help explain why New York City increased 2.1% in population from 2000 to 2010, while San Antonio increased by 16.2%, or Charlotte 32.2%. The claim of Joel Kotkin and Wendell Cox that census figures show growth primarily in "the suburbs" is little more than a truism. Growth simply occurs where there is room to grow on a clean slate, whether that growth is in high-density or low-density form.

San Antonio and Charlotte, as sprawling as they are, have distant greenfield margins. New York's dense core, by contrast, is surrounded by geographic boundaries and vast areas of very low-density residential spreading far north into Westchester and Fairfield Counties, and west into New Jersey. Houston proper, even in the absence of zoning, only experienced a 7.5% population increase within its largely built-out limits, even as its MSA grew by over 26%.

Were zoning abolished, rent control repealed, and developers given free rein in New York, could growth rates remotely comparable to sunbelt cities possibly be matched? Not likely. Even equaling Houston's growth rate – a city with abundant vacant land in and around its downtown – would probably be a challenge. Affordability is an even more distant goal using supply-based strategies alone. Relaxing development restrictions that worsen affordability and hinder supply is a crucial goal, but not one which is likely to lead to rapid population increases, or housing cost relief, in built-out and geographically-constrained cities.

Friday, March 9, 2012

In the comments to the previous post, Nicolas Derome linked to an interesting residential development outside Toronto (very close to a major planned DPZ project) which appears to have adopted the garage-parking-under-square approach. Google's streetview has covers this development, allowing you to explore it on your own, but in the aerial view below the essential elements are all visible:

The two large, curving ramps in the center square lead down to the garage. Throughout the development, stairways lead from sidewalks directly into the garage area. There is no above-ground garage parking (with all the aesthetic and space-saving benefits which flow from from that), although there are a handful of on-street spaces. Streets are 30 feet from curb to curb in most places, although one street, designated as an emergency access lane, is only 14 feet with no sidewalk.

The design is very much Garden City, resembling a somewhat denser Radburn (or any one of dozens of low-rise American public housing projects) with segregated paths for automobile and pedestrian traffic. In the absence of any use but residential, there is no pretense of urbanism here. Without places to walk to, the advantage gained by stowing the cars underground is not exploited.

Could a similar design be adapted to traditional urbanism? I've shown the example of Bastia, or a larger city such as Mannheim, or Savannah, but in each case the underlying theme is simply moving the built elements closer together, whether in a grid or in a more organic layout:

Would any attempt to integrate garage ramps into a dense urban environment fall victim to "overblown traffic engineering and design codes," as Marc mentions in the earlier comments? It is difficult to imagine anything as modest and and sensitive as the Bastia and Mannheim examples being allowed in the United States, but this Canadian development shows at least that it can be an economically viable design approach.

Friday, March 2, 2012

Austin Contrarian's Chris Bradford, who has closely examined parking in and around Austin's downtown, wrote back in December that sometimes parking regulations don't matter. Even where parking minimums are low or absent, location is central and transit is accessible, developers may still pile on the parking to accommodate high levels of car ownership among affluent tenants and owners or lack of walkable options in a neighborhood that is in the early stages of development.

This creates a challenge for the emergence of pedestrian-centric neighborhoods in formerly underpopulated or undeveloped areas, since the first new residents to arrive in such a location will necessarily be somewhat isolated and dependent on car travel for a wide range of needs, even where transit is adequate. Once ample, cheap and convenient parking is in place, the habit will be difficult to break. Maximum parking standards, or requirements that parking be placed underground or "lined" by other buildings, may not always be feasible and, in any event, address only part of the problem.

What if, instead of reacting to the parking supply provided by developers, cities anticipated demand and acted to provide a reasonable amount of supply in a manner that minimizes the adverse impact of parking structures on an increasingly walkable area?As an example, at right is an image of a city square in Bastia, Corsica.Surrounding the square is urbanism of the hyper-dense Genoese variety (Genoa governed the island for around 400 years), with apartments rising straight up from very narrow streets. The square has been excavated for a major municipal parking lot, the unobtrusive entrance to which is visible in the image.In this case, the city long predated the garage, but why not proceed in the reverse order?

Adaptation of old city squares to host parking is very common throughout Europe, and has made occasional appearances in the United States as well.Savannah's centuries-old Ellis Square, over which a parking structure was built in the 1950s, was recently reconstructed with an underground parking garage.Nashville's Public Square, which I mentioned last week, now has a multi-story garage beneath it topped by an award-winning green roof.

In most cases, these parking facilities are intended to cater to commuters or shoppers, but there is no reason they couldn't serve permanent residents as well. Combined with maximum or underground parking requirements, a city taking this approach could potentially strike a balance between a walkable and dense urbanism with high-quality public spaces and a reasonable opportunity for car storage.

A significant hurdle would be overcoming the tendency for public parking authorities to underprice parking.Taking the approach advocated by Donald Shoup, the purpose of such a garage would not be to guarantee a space to all – an impossibility, if high density is a goal – but to establish a price that leaves at least one space available at all times.

The intended goal would be a car-lite environment in which parking is permitted only to the extent of providing residents the limited option of a parking space that is neither cheap nor perfectly convenient, but which has a minimal effect on an otherwise pedestrian-centric urban environment. Would a plan like this work in practice? Would investors shy away? Would the return on investment from a more intensively built downtown, relieved of the cost burden of expensive parking structures that occupy valuable real estate, outweigh the cost of the garages? There are a lot of questions here, but there must be a better alternative to the parking-heavy urban infill currently appearing in many downtown areas.